The present invention is directed to a method and apparatus for applying a compound of a metal and a reactive gas onto a surface, and more particularly, to provide a repair tool for repairing a flat panel display. In particular, the present invention may be used to repair an indium tin oxide (ITO) or zinc oxice (ZnO) transparent conductor. This can be accomplished by using an alloy metal source oft he desired metal which is deposited by a liquid metal cluster ion source and combined with an atomic oxygen source to produce oxide thin films.
Almost all types of flat panel displays require use of transparent conductors to define the pixels. This is true for liquid crystal, electro-luminescent, field emission and plasma displays. As these display sizes are getting bigger and bigger, it is becoming more and more important to be able to repair a small number of defects on each one of these panels. Several techniques exist for the repair of electrical conductors such as aluminum and other metals, but there are no available techniques to repair transparent conductors such as indium tin oxide (ITO) and zinc oxide (ZnO) which are two of the most popular transparent conductors.
Liquid metal cluster ion source deposition is a technique whereby thin and medium layers of pure metals and alloys can be directly deposited in a desired pattern on a variety of substrates. These direct write tools have been used for mask repair or via hole etching, but they have not been used as a metal source to provide oxide or other metal and gas compound lines. That is, an oxide, nitride or other ceramic material cannot be used in a liquid metal cluster source because of the relatively high melting points required for these materials. Therefore, when the need has arisen for the deposit of a metal oxide, an alternate approach has been to use a metallic source to write metal lines and oxidize them later. However, this cannot be done for transparent conductors due to the very high temperatures required to obtain the transparency and due to the formation of other phases which degrade the electrical conductivity. Another alternative is to oxidize the metal line while it is being fabricated. One of the problems with the use of oxygen in a chamber with a liquid metal cluster ion source is that the metal on the source oxidizes faster than the deposited metal due to the high metal temperature at the source. This oxidation can poison the liquid metal source and stop proper operation of the source.
The present invention solves the problem of applying a metal and gas compound on a surface by the use of a liquid metal cluster ion source by allowing the gas to combine with the metal while it is being fabricated while isolating the gas from the metal cluster ion source.